Cover-slips are widely used for assisting and facilitating viewing objects under an optical microscope. A basic usage employs disposing the object to be viewed between a microscope slide and a cover-slip, thereby forming a stack, and placing the stack under the microscope for observation. The stack is arranged under the microscope so that the cover-slip faces the objective lens, typically meaning that the slide is arranged at the bottom of the stack and the cover-slip on top. The slide is typically relatively thick for providing some mechanical strength and stability to the stack and is typically made of a transparent material such as glass, quartz or poly(methyl-methacrylate) (PMMA), for allowing illuminating the viewed object from below. The cover slip must be transparent to allow viewing the viewed object therethrough, and is relatively thin, allowing the use of a short focal length objective. Commercial cover-slips are available in thicknesses ranging from about 0.1 mm to about 0.3 mm, various shapes, such as square, rectangular and circular, and various sizes, such as squares of 18 m*18 mm or 24 mm*24 mm.
Often, cover-slips are used as a platform for microbial culturing. Microbial culturing is used herein in a most general sense, referring to growing any microorganisms including prokaryotic cells and eukaryotic cells. For example, biological cells, bacteria, fungi or cells infected by viruses may be cultured on the surface of the cover-slip under controlled conditions, and then taken, when desired, carried on the cover-slip, for observations using an optical microscope. A typical method for microbial culturing on a cover-slip followed by microscopic observations may include placing the cover-slip in a microwell, e.g. in a microwell plate, so that one surface of the cover-slip which is adapted to assist biological culturing thereon faces upwards towards the microwell opening. Culturing may then be initiated and maintained for a desired period of time whereas the microwell plate with the cover-slip inside is kept under controlled environmental conditions possibly in an incubator. Following the culturing stage, the cover-slip may be taken for observation. The cover-slip may be removed from the microwell e.g. using a specialized tweezers and may further be manipulated, e.g. taken from place to place inside a laboratory or from one laboratory to another or may be operated on, e.g. for preparing the biological matter for microscopic observation. Such preparations may include treating cells to allow fixation to the coversilps, incubation with primary and secondary—fluorophore integrated antibodies. The cover-slip may then be glued to a microscope slide “face down”, so that the biological matter cultured on the cover-slip is disposed in between the slide and the cover-slip. Aclar®, Thermanox and Permanox™ are exemplary commercial polymeric materials commonly used for cover-slips suitable for biological culturing.